In a lithium-sulfur battery, the cathode is made of sulfur and the anode is made of elemental lithium. During electrical discharge process, the elemental lithium loses electrons to become lithium-ion, and the sulfur reacts with the lithium-ion and electrons to produce lithium sulfides. A reaction equation is: S8+16Li++16e−1=8Li2S. A lithium-sulfur battery has advantages of low-cost, environmental friendliness, good safety, and high theoretical specific capacity.
A separator is an important component in the lithium-sulfur battery. The separator separates the cathode and the anode to avoid an internal short-circuit. A conventional lithium-sulfur battery separator is polypropylene (PP), polyethylene (PE) or other non-polar film. However, polysulfides (Li2Sx, 4≤x≤8) formed during an electrical discharge process can be easily dissolved into an electrolyte, which affects a cyclic performance and a coulombic efficiency of the lithium-sulfur battery. It is difficult for conventional lithium-sulfur battery separators to inhibit polysulfide diffusion. With a great loss of active sulfur, a “shuttle effect” occurs between electrodes. Thus the specific capacity and cycling stability of the lithium-sulfur battery would be limited.
Therefore, there is room for improvement within the art.